Concrete roof



Oct. 24, 1950 R. w. RUMBLE 2,527,035

CONCRETE ROOF Filed April ll, 1947 2 Sheets-Sheet l iwvew'roa. Roy \NWMAM RUMBLE y 1 Mu rm R. W. RUMBLE Oct. 24, 1950 CONCRETE ROOF 2 Sheets-Sheet 2 Filed April 11, 1947 Iwvewrofl. Roy WIN-1AM RVMBbL.

Patented Oct. 24, 1950 OFFICE CONCRETE ROOF Roy William Rumble, Pretoria, Transvaal,

Union of South Africa Application April 11, 1947., Serial No. 740,903 In the Union of South Africa April 16, 1946 This invention relates to roofs comprising a base and a roof slab; the roof slab being spaced above and connected to the base by vertically extending structure extending between them; and said base and roof slab being moulded in position from material that is moulded in a plastic condition, and being then caused or allowed to set, becomes solid building material. Such material is herein referred to as concrete.

In my prior patent application Ser. No. 599,- 427, I have described a roof of this class in which both the base and the roof slab are moulded in position from plastic concrete and the vertically extending structure is also moulded in position.

According to this invention in a roof of the kind described in the last paragraph but one, the ertically extending structure is 'pre-formed and its lower and upper ends are incorporated in the base and roof slab respectively when said base and roof slab are moulded.

The aforesaid base is a structure resting on the walls or wall equivalents and having mainly horizontal extension. It is either a solid slab; or the equivalent of a solid slab modified by aperturing such that the supporting properties of a solid slab in respect of the vertically extending structure are preserved; for example a group of horizontal beams.

In the case of a fiat roof it is convenient to make the general plane of the roof slab parallel to the general plane of the base; but in a pitched roof the roof slab is inclined to the horizontal.

Regarding the nature of the vertically-extending structure, said structure comprises a number of metal rods spaced horizontally from one another and extending between the base and the roof slab with their individual ends incorporated by moulding into the material of said base and roof slab.

The rods are each bent alternatively back and forth in a single plane to zigzag shape and arranged vertically.

The legs formed by bending the rods are either progressively shorter from the centre of each rod outwards, with the upper bends to each side of the centre in a straight line with one another to form a unit which is triangular in side view and therefore conforms with the cross-sectional shape of a pitch roof; or the legs are of equal length for use in a roof in which the base and the roof slab are parallel.

In either case, the base and the roof slab may be spaced vertically apart at least at those edges of the base which are transverse to the extent 6 Claims. (Cl. 1081) 2 I of the rods, and the roof slab may project beyond those edges to form overhanging eaves.

The rods are preferably such as are easily and cheaply available, and readily bendable concrete reinforcing rod being particularly suitable.

The general nature of thevertically-extending structure is such that there may be detachably or displaceably secured to it means, such as cleats, suitable to support shuttering for moulding the roof slab, the method of support being such that said shuttering may be lowered away from the set roof slab after the removal or displacement of said means,

The invention is illustrated by the examples shown in the accompanying drawings, in which- Figure I is a perspective view of a pitched roof in several stages of construction.

Figures II and III are perspective views of of other forms of a pitched roof.

Figure IV is a perspective view of a flat roof.

Figure I shows a roof comprising a ceiling slab 2 carried by side walls 3, and the roof slab 4; both slabs 2 and 4 being moulded in situ.

The shuttering for the ceilingslab is that described in my prior patent application Serial No. 599,427. Cross girders 5 of T section are temporarily supported by their ends 6 being received into'gaps I formed on the tops of the walls 3 and resting on removable blocks or wedges 8. Brackets 9 are removably secured to the inside face of the gable walls Ii). shuttering panels ll forming a temporary floor are laid on said girders and brackets and the ceiling slab 2 is cast on said fioor and over the tops of the walls 3. A metal mat I2 is usually laid down so as to become incorporated in the setconcrete. When the slab 2 has set, the brackets 9 are removedn The blocks or wedges 8 are also removed, allowing the girders 5 and panels H to drop clear of the moulded ceiling slab 2. The girders 5 are withdrawn endwise; allowing the panels to be taken down. This shuttering system'forms no part of the present invention.

According to the invention, there is provided a number of the units l3 of the vertically extending structure. Each is made of concretereinforcing bar, bent back and forth to form a number of legs M united to one another by the bends" l 5, l5a at their'ends. Moreover the legs M are of graded lengths to'make the profile of the unit similar to the cross section of the roof structure. That is to say, the lower bends l5a are arranged in a horizontal line [6 corresponding to the transverse section of the roof slab, whilst the legs increase in length from both ends 3 of the unit to its centre, bringing the upper bends l5 into two lines I! and I8 sloping upward from their ends to meet one another at the point [9 corresponding to the ridge of the roof. This device provides both vertical support and diagonal bracing.

After the mat l2 has been laid, and before the ceiling slab 2 is poured, a number of the units 13 isstood upright on the mat I2, like roof trusses, and their lower bends 15a are tied to the mat l2 by ties 20. They are temporarily supported and the ceiling slab 2 is then so poured that the mat l2 and the lower bends |5a become incorporated in it. The units l'3become selfstanding when the slab 2 has set as appears at 1 the right hand end of Figure I.

The next step uses the self-standing units [3 to support the shuttering for the roof slab. Pairs of cleats 2|, 22 are provided; one being placed at each side of a pair of legs I4, [4 meeting at theupper bend I5, near to; the latter; andthe.

pair of cleats 2|, 22.; is-clampedto the legs 14, l 4tby1a1throughzbolty23. shuttering panels 24 are rested onthe clamped cleats=2|, 22-and are so positionedrelatively .to the upper bends l5 that-the latter-extend'above themto a proper height-to beincorporated into the slab cast on the shuttering panels.

The'gaps 25 between; the paneledges 26 .caused byythe legslkcorning. between them are. covered bythin slips' 2'l. shuttering-pieces 28 to mould the edgesofthe eaves are put into position, as is also a reinforcing maty29-pwhich is tied to the upper bends I5. The -roofslab-4 'is then cast on the; shuttering 30; incorporating said mat-29 andlsaid upper bends l5'into itself. The pairs of cleats 2l, ,22 are then loosened and removed byia-rworkman insidethe roof and-the panels 39 (and slips 2'!) arewithdrawn. They are conveniently withdrawn through an open gap 3| between the ceiling slab:2;and the roof slab 4, as indicated by-the arrow A; said gap 3| being conveniently left -to :provide ventilation of the roof cavity'32- and beingprotected'by the roof slab 4 being-extended as an overhanging eaves 33.

FigureII shows;a roof structure similar to that of Figure- I, but:in-which the ceiling slab 2-is omitted andits-place taken by a series of cross beams 34. In the case ofa-n open-sided building said beams 34 rest on separate pillars 35. The beams are moulded to incorporate the lower bends I511 of the units l3; and the procedure thereafter may be that described in connection with-Figure I except that the absence of a ceiling simplifies the removal of the shuttering from the roof cavity 32a. In the completed roof the roof slab 4a providesa rigidconnection between the initially separate pillar and beam units.

Figure HI shows another form of pitched roof in which the units |3a extend parallel'withthe ridge 36. In thatcase said units l3a. are-of uniform height along its length-and the several units on either-side of theridge diminish-successively in height. This form maybe-combined with the Figure I form; providing'diagonal bracing of the roof in two directions.

Figure IV shows aflatroof 4b with the flat ceiling slab 2a and flat-roof slabspaced apart bya few-inches, formingin effectone hollow slab; the reinforcement units l3b being of corresponding uniform and low height. In erecting this roof the units l3b are moulded into the ceiling slab 2a as in the first example. Owing to the small and uniform distance separating the slabs 4b and 2a, it is convenient to use a number of devices 31 in the nature of expansible cores which are laid on the formed ceiling slab 2a and provide an upper surface 28 on which the roof slab 4b is cast in a position to incorporate into itself the upper bends [5 of the units l3b; said devices 31 being such or so supported that their uppermoulding surface 38 can be lowered from under the formed roof slab 4b so that the latter remains supported on the units [3b.

I claim:

1. A roof comprising a base as herein defined and a roof slab, the base and the slab being spaced vertically apart and both base and roof slab being of concrete, and comprising also a number of metal rods each bent alternately back andiforth in a single plane to zig-zag shape :and arranged vertically-with the lower bends incorporated in the material of the base and the upper ends-incorporated in the material of the roof slab, the variousrods being arranged parallel with each other and spaced horizontally apart and being-continuous across the roof.

2. The roof claimed in claim 1 of gable shape in which with respect toeach rod the legs resulting from bending the rod to zig-zag shape ,are progressively shorter from the centreofzthe rod outwards, with the upper bends to each side of the centre in a straight line witheach other to form a unitwhich is triangular inside view.

3. The roof claimed in-claim Lin-which the roof slab and thebaseare parallel and in which, with'respect to'each -rod, the legs are of equal length, with the upper and lower bends in straight lines-with each other, the lines being parallel.

4. The-roof claimed in claim lin which the rodsare concrete-reinforcing bars.

5. A roof comprising a base'as h'ereindefined and'a roof slab, both-base and roof slab being of concrete, and comprising also a number of metal rods each bent alternately back and forth in a'single plane to zig-zag shape and arranged vertically with the lower bends incorporated'in the material of 'thebase and theupper ends incorporated in the material of i the roof slab, the various-rods being arranged parallel with each other and spaced horizontally apart, and being continuous across the roof; the base and the roof slab being spacedvertically apart and the roof slab projecting beyond the base to form-overhanging-eaves at'least at the edges of the slab which ar spaced from the roof slab.

6. The rooftclaimed in claim 5 irrwhichvthe rods are concrete-reinforcing bars.

ROY WILLIAM RUMBLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES 1 PATENTS Number Name Date 2,088,645 Fling Aug. 3, 1937 2,108,065 Kotibaty Feb. 15,1938 2,275,056 White May 3, 1942 

